The Audigy SE is not an emu10k1 chip, and will not work with any of the drivers that ship with FreeBSD. It should work with OSS from ports, though. Having said that, I don't think you'll really notice any difference in the quality or performance of the audio.

As I said, the emu10kx driver is in the base system (and has been for at least most of the 7 series and all of the 8 series). I do not believe it supports any more soundcards than the emu10k1 driver also in the base system and, iirc, the Audigy LS is not an emu10k* soundcard.

ossinfo should show you what driver OSS is using, and my guess is that it won't be oss_sblive.